Method of and system for managing documents in a bandwidth constrained environment

• US 6,438,548 B1
• Filed: 06/30/1999
• Issued: 08/20/2002
• Est. Priority Date: 06/30/1999
• Status: Expired due to Term

• Current Assignee: LinkedIn Corporation (Microsoft Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Williams, Michael Lindsey, Plock, Christopher B., Marquette, Brian N., Grim, Clifton E. III, Wilson, John D., Stevens, Mark B.
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): NGUYEN, CAM LINH T
• Application Number:
  US09/345,180
• Time in Patent Office: 1,147 Days
• Field of Search: 707/8, 707/100
• US Class Current: 1/1
• CPC Class Codes: G06F 2209/522 Manager
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/289 Intermediate processing functionally located close to the data consumer application, e.g. in same machine, in same home or in same sub-network
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A system for managing documents in a distributed computing environment, which may be bandwidth limited, includes a document locker server and a document locker client. The document locker client monitors user interaction with a version of a document locally replicated from a document server. Whenever the user attempts interaction with the document, such as editing or performing a workflow action, which would change said document, the document locker client requests a lock for the document from the document locker server. The document locker server grants a lock if the document is not already locked by another user and the document locally replicated is the latest version of the document. The document locker client allows the user to perform the operation if a lock is received, without having to replicate a version of the document to the local host.

Claims

1. A method of managing documents in a distributed computing environment, which comprises the steps of:

monitoring user interaction with a version of a document locally replicated from a server, said document being identified by a document identifier and version identifier;

whenever said user attempts an operation during user interaction with said document that would change said document, requesting a lock for said document by sending a lock request to a document locker server;

determining if said document is already locked for another user by checking a locked document table accessible by said document locker server, said locked document table including, for each locked document, a document identifier, a version identifier, a lock identifier, and an identifier for the user for whom said document is locked;

if said document is not already locked for another user, determining if the version of said document locally replicated is the same as the version of said document stored on said server;

if the version of said document stored on said server is newer than the version locally replicated, informing said user that a newer version of said document exists and prompting said user to replicate said newer version from said server;

if the version of said document locally replicated is the same as the version of said document stored on said server, locking said document by sending a lock including a lock identifier to said user, and placing said lock identifier in said locked document table with the identity of the document being locked;

inserting said lock identifier into said locally replicated document;

allowing said user to perform said operation and to replicate said locally replicated document including said lock identifier to said server if a lock is received; and

preventing said user from performing said operation if a lock is not received.

2. The method as claimed in claim 1, including the steps of:

periodically comparing the lock identifier for said document in said locked document table against the lock identifier inserted in the version of said document stored on said server; and

;

deleting the entry for said document in said locked document table if said lock identifier for said document in said locked document table matches the lock identifier inserted in the version of said document stored on said server.

3. A system for locking documents in a distributed document management system comprising;

a document server and at least one client machine;

a document locker client on said at least one client machine, said document locker client further comprising;

means for monitoring user operations on a version of a document locally replicated from said document server;

means for sending a lock request message to a document locker server, said lock request message including an identifier for said locally replicated document, said lock request message requesting a lock from said document locker server whenever said user attempts to perform an operation that would change said document;

said document locker server further comprising;

a list of locked documents, said list of locked documents including for each locked document, a document identifier, a version identifier, an identifier for the user by whom said locked document is locked, and a lock identifier;

means for determining if the document identified in said lock request message is a document listed in said list of locked documents to determine whether said locally replicated document is locked by another user;

means for notifying said document locker client that said locally replicated document is locked by another user. means for determining it said version of said locally replicated document is the most recent version of said document;

means for granting a lock if said document is not locked by another user and said locally replicated document is the most recent version of said document, said means for granting a lock including means for making an entry in said list of locked documents, said entry including an identifier for said lock,

means for sending a lock granted message to said document locker client, said lock granted message including said identifier for said lock; and

wherein said document locker client further comprises;

means for writing said identifier for said lock in said locally replicated version and allowing said user to perform said operation and to replicate said locally replicated document including said lock identifier to said document server if a lock is received; and

means for preventing said user from performing said operation if a lock is not received.

4. The system as claimed in claim 3, wherein said document locker server includes means for comparing lock identifiers in said list of locked documents against lock identifiers written in documents on said document server.

5. The system as claimed in claim 4, wherein said document locker server includes means for deleting an entry in said list of locked documents if the lock identifier for said entry matches a the lock identifier in said document on said document server.